Air conditioning unit of the room cooler type



Oct. 30, 1956 w. MOGRATH 2,768,514

- AIR CONDITIONING UNIT-OF THE ROOM COOLER TYPE Filed Jan. 2. 1955 iinited States Patent AIR CONDITIONING UNIT OF THE ROOM COOLER TYPE William L. McGrath, Syracuse, N. Y., assignor to Carrier Corporation, Syracuse, N. Y., a corporation of Delaware Application January 2, 1953, Serial No. 329,380

2 Claims. (Cl. 62-129) This invention relates to an air conditioning unit and,

more particularly, to a self-contained air conditioning unit or". the room cooler type containing-provision for ventilation.

Room coolers are frequently operatedwith an outside air damper in the open position to provide ventilation. Unfortunately, however, the. user often discontinues operation of the unit while forgetting to close the damper to prevent access of outside air into the unit. This is highly undesirable since such practice permits air to enter the room without being filtered to remove dust and dirt particles and permits street noises in much greater intensity to penetrate the room. Too, when the user forgets to close the damper of the unit, it frequently remains open during the winter season with resulting drafts in the area and increased costs of heating the area.

The chief object of the present invention is to provide a self-contained air conditioning unit in which these disadvantages are obviated.

An object of the present invention is to provide a selfcontained air conditioning unit containing means toassure operation of the evaporator fan at all times the damper of the unit is in an open position to assure filtering ot' the fresh air directed into the unit and to make it obvious that the vent damper is open.

A further object is to provide a self-contained air conditioning unit containing a simple control arrangement actuated by movement of the damper to insure energization of the fan motor to permit ventilation air to be supplied to the room being treated even though the unit is not performing a cooling function and to assure passage or air through the cooling element of the unit when the unit is performing a cooling function regardless of movement of the damper.

A still further object is to provide a self-contained air conditioning unit having a simplified control arrangement to assure ease of operation by the user. Other objects of the invention will be readily perceived from the following description.

This invention relates to an air conditioning unit which comprises, in combination, a casing, means in the casing to cool air, a fan to direct air through the cooling means, means to actuate the fan, means to admit ventilation air within the casing, and means to assure actuation of the fan when the ventilation means is in air admitting position.

The attached drawing illustrates a preferred embodiment of the invention, in which Figure l is an isometric view of a self-contained air conditioning unit embodying the present invention; and

Figure 2 is a schematic view of a wiring diagram of the unit.

Referring to the drawing, there is shown a self-contained air conditioning unit 2 in which the various elements of the unit are assembled on a base 3. A casing 4 shown in dotted outline in Figure l is placed thereover to form the complete unit. it will be understood the various elements may be combined with the casing to ice form the unit if desired rather than being assembled on a base with the casing disposed thereover.

The casing 4 cooperates with a partition 5 to separate the unit into two chambers 6, 7. Placed within chamber 6 is the high side of the refrigeration system while the low side of the refrigeration system is placed in chamber 7. The high side of the refrigeration system includes a hermetic motor-compressor unit 8 connected to condenser 9. A fan 10 is provided to direct air through the condenser, a motor 11 serving to actuate the fan. The low side includes capillary 12 regulating flow of refrigerant from condenser 9 to evaporator 13. A suction line (not shown) connects the evaporator 13 with the compressor. A filter 14 is placed adjacent evaporator 13 in order that dust and dirt particles'in the air directed through the evaporator may be removed. Fan 15 driven by motor 16 directs air through evaporator 13.

The casing is provided with suitable grilles (not shown) to permit fan 15.to draw room air into chamber 7, the fan directing such air through evaporator 13 to cool the same and discharging the cooled air into the room.

To permit ventilation air to be supplied to the room, an opening 17 is provided in partition 5, the opening being closedby a damper 18 movable through linkage 18'. When the damper is moved to an open position, fan 15 draws ventilation airwithin chamber 7, mixing the ventilation air with the room air and discharging the same intothe room.

A two-position single pole selector switch 19 is provided to place the unit in operation. When switch 19 is closed, the compressor motor, condenser fan motor and evaporator fan motor are energized to actuate the compressor and fans. As pointed out above, when the damper is in an open position it is desirable to assure operation of evaporator fan 15 regardless whether the compressor of the refrigeration system is or is not in operation. For this purpose, damper switch 29 is provided. It will be understood, of course, the various motors and switches are included in an electrical circuit connected to a source of electrical energy designated at L1, L2. Damper switch 20 may be a single pole double throw switch with no off position and contains a movable arm 21 through which the switch is moved from one position to a second position. Arm 21 is placed in a position in which it is moved by movement of damper 18.

In Figure 2, there is shown a wiring diagram of the unit illustrating the manner in which the various operating elements are electrically connected. The power supply designated at L1, L2 is connected to the selector switch 19 at terminals 25, 26. Switch 19 also contains terminal 27 which is connected to terminal 26 when the switch is placed in closed position by pole member 23. Connector 7 29 connects terminal 25 of switch 19 with terminal 30 of evaporator fan motor 16. Terminal 31 of motor 16 is connected by connector 32 to terminal 33 of damper switch 20, the pole 34' of switch 20 normally connecting terminal 33 to terminal 34 of switch 20, terminal 34 being connected to terminal 27 of switch 19. Terminal 35 of switch 29 is connected by connector 36 to terminal 26 of switch 19.

The relay 37, compressor motor 8, condenser fan motor 11 and starting capacitor 38 are connected in the usual manner to terminals 25, 27 of switch 19 for energization. Since this portion of the circuit is well-known and customary in the industry, it is believed extended description is not required.

Considering the operation of the device, assuming the damper 18 is in normally closed position, switch 3.9 is

closed by connecting terminals 26, 27 thus closing the started. The locked rotor surge ofcurrent energizes a magnetic coil 40 in the relay 37 closing contacts and completing the starting capacitor circuit to the compressor starting winding. As the compressor speed increases, the initial locked rotor current surge decreases; the magnetic coil is deenergized opening the contacts and the starting capacitor circuit is removed from the compressor starting windings.

Simultaneously, when the contacts 26, 27 of switch 19 are closed, the circuit energizing motor 16 is closed, current flowing from terminal 25 through connector 29, motor 16, contacts 33, 34 of switch 20 to terminal 27 of switch 19. This is normal operation when the unit is employed to cool room air, damper 18 being in a closed position.

When damper 18 is moved to an open position, movement thereof moves arm 21 of switch 20 shifting the position of the pole 34' to connect terminals 33, 35 of switch 20 permitting the fan motor energizing circuit to remain closed and operation of the fan motor to continue through terminals 25, 26 of switch 19. Assuming it is desired to discontinue the cooling functions of the unit, switch 19 is opened, breaking the connection between terminals 26, 27 and opening the compressor and condenser fan motors circuit. However, operation of the evaporator fan motor continues for the damper is open and the fan motor is operated through terminals 33, 35 of switch 20 to maintain a closed circuit. If it is desired to discontinue operation of fan 15, it is necessary to close damper 18 again shifting the contacts of switch 20 to the first circuit (terminals 26, 27 of switch 19) which at that time is open so the fan motor is deenergized.

The present invention provides an air conditioning unit having a simple control means which assures operation of the evaporator fan motor when the damper of the unit is open to admit ventilation air within the unit so that the fan may perform the dual functions of supplying ventilation air to the room and is also actuated on cooling to supply cooled air to the room. The invention assures that ventilation air entering the room is filtered to remove dust and dirt particles; operation of the fan reminds the user to close the damper so that drafts and diflicult heating conditions are not created in the room under severe weather conditions.

While I have described a preferred embodiment of the invention, it will be understood that the invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

1. An energizing circuit for an air conditioning unit including a damper to close a passage for admission of ventilation air to the unit, having a compressor motor and a fan motor which includes a multi-position switch connected to a source of electrical energy, said switch in closed position energizing said motors, and a second switch requiring energization of said fan motor at all times the damper of the unit is open without regard to the position of the first switch.

2. In combination with an air conditioning unit including a compressor, a prime mover therefor, a damper to close a passageway for the admission of ventilation air to the unit, a fan, and a motor therefor, an energizing circuit including the prime mover and the motor connected to a source of electrical energy, a multi-position switch in said circuit adapted to energize the prime mover and the motor when a damper of the unit is in closed position, and a second switch in said circuit requiring energization of the fan motor at all times the damper of the unit is in open position and the prime mover is deenergized by opening of the first switch.

References Cited in the file of this patent UNITED STATES PATENTS 2,081,107 Kilb May 18, 1937 2,290,973 Jewell July 28, 1942 2,343,121 Eberhart Feb. 29, 1944 2,451,366 Terry Oct. 12, 1948 

